Railway signaling



March 6, 1928.

. 1,661,508 E. C. SASNETT RAILWAY SIGNALING Filed Jan. 20. 1926 Patented Mar. 6, 1928.

UNITED STATES EDWARD C. SASNETT, OF WASHINGTON, DISTRICT OF COLUMBIA.

RAILWA Y SIGNALING.

Application filed January 20, 1926. Serial No. 82,532.

The present invention relates to railway signaling and particularly to signaling systems of this character in which, the indica tions are controlled by current impulses of differing character. The invention is illustrated as applied to the signaling of an electrically operated road, the third rail,'or power iconductoiy being employed for the transmission of the signaling impulses, but the invention is equally applicable to roads of other character. 7 r i Referring to the accon'ipa-nying drawing, which shows diagrammatically a system embodying the invention The track rails and the power conductor are divided into insulated blocks A, B, C, 1 etc, the insulated joints being bridged by inductive bonds to permit the passage of propulsion current but to divide thetrack and third rail into sections with respect to the signaling current, in a. manner well understood by those skilled in this art. Connected across the track rails at the entrance ends of the blocks are track relays 10", 10, 10 etc., and associated with each track relay is a motor operated switch mechanism for controlling the application of energy to the exit ends of the blocks.

This switch mechanism is operated by a single phase motor 11, ll etc. The armatures of these motors are rigid with worms 12 meshing with worm wheels 13 secured to shafts 14, to each of which is secured a cam disk lzllnwlng a raised portion extending through an arc of 180, the said raised portions periodically operating switches 16", 16, 16* etc. Each shaft 14: drives through gear wheels 17 at a reduced speed a shaft 18 on which are secured wheels19 and 20.

Piroted on shaft 18 adjacent said wheels are arms 2i and 22 which carry pawls en aging the peripheries of the wheels, where y the arms are freely rotatable in a counterclockwise direction, but are constrained to counterclockwise direction when this solenoid s energized. Similarly, arm 22 is connected to the plunger of a solenoid 26.

The track relays are of the three position type, having a winding connected across the track rails and a winding 27 energized by current of the same frequency as that of the track circuit current but displaced in phase therefrom. The movable contacts of these relays occupy a neutral, or central, position when the track windings aredeenergized, and occupy a position. 'to'one side or the other of the central position when thetrack current is off one relative polarity or the'opposite relative polarity, as is well understood by those skilled in this art.

Signaling currents of two different frequencies are employed in the system illustrated, the said currents being supplied by alternator-s 28 and 29 connected respectively toline wires 30 and ill and a common wire 32. The frequencies of the two currents may for example be and 120.

Normally the track circuit current flows continuously but its relative polarity is periodically reversed by the operation of switches 16, as will hereinafter appear.

Hence normally the movable contacts of the I track relays vibrate from one position to the other with a frequency depending upon the operation of switches 16. When the movable contacts of the track relays occupy either operated position the circuits of solenoids 26 are closed, each of said circuits beingfrom one side of transformer 35, conductors 36,37 and 38, either contact 39, conductor e0, solenoid 26, and conductors 4:1 and 42 to the other side of the transformer. The circuit of solenoid-25, however, is closed only when the movable contacts of the track relays occupy their left hand positions. This circuit as follows: from one side of transformer conductors 3 37, 38 and 43, contact 44, conductor 45, solenoid 25, and conductors -1. and 4-2 to the other side of said transforn'ien' Normally, therefor-e solenoids 26 will be substantially conti'uously energized and solenoids 25 will be intermittently energized. .AI'IDQQ will accordingly be raised, and the front contacts of switches 24 will be clcsediwhile the hack contacts thereof will be open. The intermittent energizations of solenoids 25 under normal conditions will be of such frequency that arms mittently applied thereto the alternating potential of transformer 54, due to the intermittent movement of the contacts of relay 10" from their middle to their left hand positions, and the vehicle in, block A would receive an intermediate speed indication. The third rail section of block B has applied thereto intermittently the alternating potential of transformer 50, due to the movements of track relay contacts 10 to the right, and if t-he vehicle in block A should advance into block Bit would receive a slow speed indication. The third rail section for block C is not supplied with alternating sig naling energy, due to the neutral position of the movable contacts of relay 10., so that if the vehicle should advance into this block it would receive a danger or stop indication.

It will be observed that the motors 11 and 11 are energized respectively from transformers 54 and 35 connected respec tively to line wires 30 :and 31. Thus if one frequency of the signaling current is twice that of the other the motors at these two stations will operate at different speeds, one motor operatin twice as fast as the other, and consequent y one cam disk 15 operating at twice the angular velocity of the other and causing its associated switch 16 to operatetwo times to one operation of the other switch. I i

In the application of the invention to electrically operated roads it is designed to have the switches 16 at adjacent stations operate at different frequencies, and the switches 16 at alternate stations operate at the same frequency, fqr a purpose hereinafter explained. The different frequencies of operation of switchesat adjacent stations can There are provided on the vehicle two relays ,60 and 61 connected at one side to a contact, 62 engaging the third rail and connected at the other side to the Wheels and axle of the vehicle. These relays are made selectively responsive to the respective fre quencies used in the system, relay 60 being made responsive to the frequency oftransformers 54 and relay 61 to the frequencyof transformers 50.

When relay 6() is energized and relay 61 deenergized, the following circuit is closed: 7

from the negative battery lead, front contact 63, back contact 64, conductor 65, solenoid 66 and conductor 67 to the positive bat.- tery lead. When relay 60 is deenergized and 61 energized, the following circuit is closed: negative battery lead, back contact 68, front contact 69, conductor 70, solenoid 71,, and conductor 7 2 to the positive battery lead.

Sincefunder clear conditions the secondaries of transformers 50 and 54 are alter nately and-periodically connected to the third rail sections, it will be clear that under these conditions relays 60 and 61 will be alternately and periodically energized and will in turn cause the solenoids 66and 71 to be alternately and periodically energized.

-The plunger of solenoid 66 is connected to an arm'73 pivoted ona shaft 74 that .is driven through suitable worm gearing175 at a predetermined angular velocity by a motor 76. Fixed-on shaft 74adjacent arm 7 3 is a wheel 77, the periphery of which is engaged by a pawl carried by arm7 3, whereby when solenoid 66 is energized arm 73 is rotated instantly to the limit of its counter-clockwise movement, but when the solenoid is deenergized arm 7 3 rotates in a clockwise direction with wheel 77. WVhen arm 7 8 approaches the limit of its clockwise movement it engages and op-ensthe contacts of a switch. Connected to the plunger of the solenoid 71 is an arm 7 9 having a pawl engaging the periphery of a wheel fixed on shaft 74, and this arm also is adapted to engage and open the contacts of a switch 81 p at the termination of a predetermined interval following the deenergization ofits associated solenoid. Under clear conditions the solenoids 66 and 71 are alternately energized at such frequency that neither arm 7 3 or 79 reaches a position where it opens the contacts of switch 78 or 81, and under these conditions the following circuit is closed: positive battery lead, conductor 82, contacts 83, conductor 84, contacts 85, conductor 86, clear lamp 87, conductor 88, front contacts 89 and 90 of a pair of relays 91 and'92 and conductor 93 to the negative battery lead. Relays 91 and 92 are normally energized through circuits hereinafter indicated. It will be noted that solenoid 127 is in parallel with lamp 87, fora purpose which will here inafter appear.

Under medium speed conditions (the third block in advance occupied) transformer 51; only will be intermittently connect'ed to the third rail section. Therefore under these conditions relay will intermittently pick up. but relay 01 will be con tinuously deenergized. Therefore solenoids 66 will be intermittently energized; but solenoid 71 will not be energized. Hence a short time after the vehicle enters a block in which these conditions obtain arm 79 will have opened the. contacts of switch 81, thereby openin5 the circuit of clear lamp 8? and closing the following circuit: positive bat tery lead. conductor 82. back contacts 9-1. conductor 05. a lamp 90. conductor 88, front contacts 89. 00 and conductor 93 to the negative battery lead.

Under slow speed conditions (the second block in advance occupied) the secondary of transformer will be intermittently connected to the third rail section. and accordingly relay 01 only will be intermittently energized. thus intermittently energizing solenoid T1 and causing solenoid 0 to be continuously dcencrgized. Hence arm 7? will open the front'contacts of switch 78 and close the back contacts thereof. while arm 79 will move away from switch 81. The closing of the back contacts of switch 78 closes the follmving circuit: positive buttery lead, conductor 97. back contacts 98, a lamp 99. conductor 88. front contacts 89 and 9t) and conductor 92) to the negative battery lead.

In order to prevent; a false indication by reason of a vehicle entering an occupied block, I provide mechanism controlled by the frequency of the alternating current impulses. This mechanism comprises a pair of switches and 101 controlling the relays 91 and 92 and operated by arms 102 and 1021. These arms are pivoted on a. shaft 10%. driven through suitable gearing from shaft 71. Fixed on shaft 101- adjacent arm 102 is a wheel 105 the periphery of which is engaged by a pawl on arm 102. Similarly a wheel 100 is tixed on shaft 104" adjacent arm 103 and has its periphery engaged by a pawl on this arm. Arms 102 and 1021 are connected to the plungers ol solenoids 107 and 108 respectively and these solenoids are controlled respectively by switches 109 and 110 adapted to he operated-by suitable step by step mechanism responsive to the. frequency of the alternating current impulses.

The step-by-step mechanism shown comprises a ratchet wheel 111. an arm 11.2 rigid with the ratchet wheel 111, an operating pawl 113 and a holding pawl 11%. Pawl 113 is operated by a magnet 115. the circuit of which is the following: positive battery lead, conductor 110. magnet 11:), conductor 117, a contact segment 118, a brush 119 on an arm rigid with shaft 10-1-,a contact segment 120, conductors 121 and 122, front contact 123 of relay (i1 and back contact 124 of relay tit) to the negative battery lead. A branch of this circuit includes conductor 125, back contact 126 of a relay 127, conductor 128, back contact 129 of relay (J1 and front contact 130 of relay (i0. Relay 127 is in parallel with clear lamp 8?, so that this relay will be energized when the clear lamp is displayed.

The number of energizations of magnet 11:) during the time brush 11.0 is bridging contact segments 118 and 120 will depend upon the number of energizations of relay (it) or of relay 61 during this time and will therefore vary as the vehicle passes from one block into the adjacent block, due to the different frequencies of operation of the track relay contacts in adjacent blocks. If the contacts of one track relay operate at twice the frequency of the relays in adjacent blocks, then the number of energizations of step-up magnet during the time brush 11!) is bridging contact segments 118 and will be doubled as the vehicle passes from the block of lower frequency to the block of higher frequency or will be halved as the vehicle passes from the block of higher frequency to the block of lower frequcncy. Under clear conditions, magnet 115 can only be energized through back contact 121 and front contact 123, while under medium and slow speed conditions. relay 127 being dcenergized, magnet 115 can be encrgized either through front contacts 1110, back contact 129 and back contact 126. or through hack contact 124: and front contact 122. In short, no matter whatthe frequency of the alternating current received and no matter whether the conditions be clear, medium speed or slow speed, magnet 115 will be intermittently energized at a frequency depending upon the frequency of operation of the track relay contacts.

Holding pawl 114 is operated by a magnet 132 in the following circuit: positive battery lead, conductor 1233, contact segment 134-. a brush on the arm a rigid with shaft. 104, contact segment- 135, conductor 130. magnet; 132, conductor 137 to the negative battery lead. Assuming the Vehicle to be travelling in a low frequency block, that is a block wherein the connection of energy to the third rail section is controlled by track relay contacts operating at low frequency, when the brushes on arm a engage the contact segments holding magnet 132 will be energized and the holding and operating pawls will engage ratchet wheel 111, :and magnet 115 will be energized a certain number of times stepping the arm 112 into engagen'ient. with contacts 101), whereupon the brush 119 will bridge a pair of insulated contacts segments 140, closing the following circuit: positive battery lead, conductor 1 11, solenoid 107, conductor 142,

tently energized, once on each rotation of arm 8. hen the vehicle 18 travelling in a high frequency block,the ratchet wheel will he stepped around to engage arm 112 with contacts 110 during each rotation of arm 8, and consequently when brush 119 engages contacts 140, the following circuit will be closed: positive battery lead, conductor 146,

solenoid 108, conductor 147, contacts 110, conductor 143, contacts 140, and conductors 144 and 145 to the negative battery lead.

Switch 100 is adapted to close a pick up circuit through relay 91 and a stick circuit through relay 92. The pickup circuit is from the positive battery lead by way of conductor 148, contacts 149, conductor 150, the winding of relay 91,,and conductors 151 and 145 to the negative battery lead. The stick circuit is from the positive battery lead, conductor 148, contacts 152,conductor 153, front contact 154, conductor 155, the winding of relay 92 and conductors 151 and 145 to the negative battery lead. Switch 101 is adapted to close a pick up circuit through relay92 and'a stick circuit through relay 91. These circuits'are exactly similar to the circuits last described and will be obvious from the drawing.

If the vehicle should enter a danger block,

that is, a block immediately in rearof an occupied block, it would, as previously pointed out, receive no signaling impulses, and hence neither solenoid 107 nor 108 would be intermittently energized and a predetermined time after the entry of the vehicle into suchla block, both switches 100 and 101 would be opened, causing both of the relays 91 and 92 to drop. As long as these relays aredeenergized none of the signals can be displayed, as the common return 88 of all the signals passes through front contacts 89 and 90 of these relays. If the vehicle should actually enter the occupied block, it would receive signaling impulses unless thelolock in advance of said occupied block were occupied. These impulses would lntermittently energize one or the other of solenoids 107 and 108, depending upon whether the impulses were of low or high frequency. Under these conditions one or the other of relays 91 and 92 would pick up due to the closing of its pick-up circuit at switch 100 or101, as the case may be. the relays, however, would pick up, and

Only one of I hence thc signals on the vehicle entering the occupied block could not be displayed, and

said vehicle would not receive a false indication. In short, after a vehicle has once entered a danger block and its relays 91 and 92 have dropped, it is necessary inorder to rccnerg'ize both relays that the vehicle receive signaling impulses first of one :frequency and then of the other frequency, and obviously this cannot occur until the block in advance of the vehicle has been cleared and the vehicle enters this block at a time when the block in advance thereof is clear-.

Now having particularly describeda system embodying my invention, what I claim as newand desire to secure by Letters Patent ergy across the track and. power conductor,

a vehicle havingtranslating devices connected to said power conductor and track, and signaling mechanism controlled by said translating devices.

2] In a railway signaling system for electrically operated roads, a track and a power conductor divided into blocks. track relays connected at theentrance ends of the blocks, motor operated circuit controllers for connecting'sonrces of electrical energy across V the track at the exit ends of the blocks and periodically reversing the polarity thereof to cause the trackrelay contacts to vibrate,

means for connecting sources of electrical energy across the power conductor and track controlled by said contacts, a vehicle having translating devices connected to said power conductor and track, and signaling H16Cl1t nism controlled by said translating devices.

3. In a railway signaling system for electrically operated roads, :1 track and a power conductor divided. into blocks, track circuits for the blocks including track relays, means controlled by said track relays for connecting electrical energy intermittently across the power conductor and track, the frequency with which the connections are made being different in the case of adjacent blocks, a vehicle having translating devices connected to the power conductor. signal mechanism controlled by said translating devices, and means preventing the clearance of said. signal mechanism until the-vehicle has successively received impulses of two different frequencies. v

4. In a railway traflic controlling system, in combination with a trackand a power conductor divided into blocks, means for alternately and periodically connecting: sources of alternating current of ditierent frequencies across the power conductor sections and traclt under prtalcterniirzcd traliic conditions, a vehicle having relays connected across the power conductor and track selectively respmisive to said frequencies, and vehicle governing means controlled by said relays.

5. In a railway trallic controlling system, in combination with a track and a power conductor divided into sections, means for alternately and periodically connecting two sources of alternating current of dilicrent frequencies across the power conductor sections and track under predetermined tratiic conditions. a vehicle having two relays connected across the-power conductor and track responsive respectively to said frequencies, a magnet on the vehicle havin; a circuit including the front contact: of one relay and the back contact of the other relay. a second magnet on the vehicle having a circuit including the front: contact of said other relay and a back contact of the first mentioned relay. and a signal controlled by said magnets and displayed only when both of said magnets are intermittently energized.

6. In a railway traliic controlling system, in combination with a track and a power conductor divided into sections, means for alternately and periodically connecting two sources of alternating current of different frequencies across the power conductor sections and track under predetermined traflic conditions. a vehicle having two relays connected across the power conductor and track responsive respectively to said frequencies, and a signal on the vehicle which is displayed only when said relays are alternately and periodically energized.

7. in a railway trailic controlling system, in combination with a traclc and av power conductor divided into blocks. means for impressing: electrical impulses on the power conductor sections of predetermined frequencies. the frequencies of the impulses being: different in the case of adjacent blocks and the same for alternate blocks. a vehicle having translatin; devices connected to the power conductor. vehicle governing means controlled by said translatiirc devices, means on the vehicle for integrating the impulses per fixed interval. and mechanism controlled by said integrating means for controlling said vehicle governing" means.

8. In a railway trailic controlling system, in combination with a tack and a power conductor divided into sections, means for alternately and periodically connecting two sources of alternating current of different frequencies across the power conductor and track under predetermined traliic conditions, means for periodically connecting one of said sources across the power conductor and track under different tratiic conditions, means for periodically connecting, the other of said sources across the power conductor and track under still different trafiic c0nditions. a vehicle having relays connected across the power conductor and track selectively responsive to said frequencies, and vehicle governing means controlled by said relays.

S). In a railway tratlic controlling system, the combination with a track divided into insulated blocks, of an alternating current track relay at the entrance end of each block having two windings, one of which is connected across the rails and the other of which is connected to a source of alternating: current energy, means for connecting said source of energy across the rails at the exit end of each block and for pCllOtllLfllly reversint the connections of said source to the rails. whereby the track relay contacts periodically vibrate from one position to the opposite position, and trailic controlling means governed by said relays and held at one indication only so long as said contacts thus vibrate.

10. In a railway trailic controlling system, the cmnbination with a track divided into insulated blocks, of an alternating current track relay at the entrance of each block having two windings, one of which is connectcd across the rails and the other of which is connected to a source of alternatin current energy, means for connecting sai source of energy across the rails at the exit ends of the blocks and for periodically re- \el'sing the connections of said source to the rails under predetermined tratiic conditions, whereby the track relay contacts eriodically vibrate from one position to tlie opposite position, means for periodically connecting said source to the exit ends of the blocks with one relative polarity under different traiiic conditions, means for periodically connecting said source to the exit ends of the blocks with the other relative polarity under still different traflic conditions, and tratlic governing means controlled by said relays.

11. In a trailie controlling system, in combination. a track and a conductor divided into blocks, track circuits for the blocks including track relays, means controlled by said track relays for connecting sources of electrical energy intermittently to the conductor sections, the frequency with which the connections are made being difi'erent in the case of adjacent blocks, a vehicle havin a. translating device adapted to be energize from said conductor, signal mechanism con trolled by said translating device, and means for clearing the signal mechanism when said translating device has been successively actuated by impulses of different frequencies.

Ill]

12. In a trafiic controlling system, in combination, a track divided into insulated blocks, a track relay connected across the rails at the entrance end of each block, a motor operated circuit controller associated with each track relay for connecting a source of energy across the track rails at the exit ends of the blocks and periodically reversing the polarityof said energy under normal conditions, switch mechanism associated with each circuit controller and operating when a track relay is deenergized to cause the circuit controller associated with the deenergized relay and with the track relay immediately in rear to apply energy of one polarity intermittently to the block immediately in rear of the deenergized relay and energy of the other polarity intermittently to the second block in rear, and train control mechanism selectively actuated by energy flowing in the track rails.

13. In a railway trafiic controlling system, a track divided into insulated blocks, a track relay connected across the rails at the entrance end of each block, a constantly oper ating motor associated with each track relay, switch mechanism operated by each motor adapted to connect a source of electrical en ergy across the rails at the exit ends of the respective blocks and to vary periodically the characteristic of said energy, means associated with each switch mechanism and controlled by the respective track relays for governing the application of energy by said switch mechanism, and train control mechanism actuated selectively according to the characteristic of the energy flowing in the track rails. 7

1+1. In a railway signaling system, a track divided into blocks, a track relay connected across the rails at the entrance end of each block, a constantly operating motorassociat-cd with each track relay, a circuit controller operated by each motor for connecting energy across the rails atthe exit ends of thehlocks and for periodically varying the characteristic of said energy under normal conditions, switch mechanism associated with each controller operating when a track relay is deenergized to cause the controller associated therewith and with the track relay iml'nediately in rear to apply energy having one characteristic to the block immediately inrear ot' the deenergized relay and energy of a difi'erent characteristic to the second block in rear, and trafiic con trolling means actuated selectively in accordance with the character of the energy flowing in the track rails. 1

In testimony whereof I hereunto aflix my signature. v

EDWARD G. SASNETT. 

